The film centers on Haruka Nanase as a junior high student, where he and his friends learn the meaning of teamwork as they join the swim team.

Starting Days was released nationwide in Japanese theaters on December 5, 2015, to moderate success, ranking #5 on its opening weekend and being nominated for Best Picture in the Newtype Anime Awards.

After discovering that Haruka and his childhood friend, Makoto Tachibana, had once been part of the Iwatobi Swim Club, Asahi Shiina urges them to join the swim team despite Haruka's lack of interest, while Kisumi Shigino suggests they join the basketball team.

Natsuya Kirishima, the captain of the swim team, visits their class and successfully convinces Haruka, Makoto, Asahi, and his younger brother Ikuya to join.

However, Iwatobi loses the team medley, leaving him disappointed as he gives him Rin's letter.

The next day, Ikuya threatens to quit the team and confides to Haruka, Makoto, and Asahi about feeling lonely and abandoned by Natsuya.

When the four visit Nao, who is getting surgery for a detached retina, he offers them advice on their strengths as individuals and as a team, giving them hope.

On the way home, however, Haruka faints, leading Makoto, Asahi, and Ikuya to stay at his house until his mother returns.

The letter details the setbacks Rin has faced in Australia and his desire to swim like Haruka.

[5] Several cast members from the television series returned to reprise their roles, including Nobunaga Shimazaki,[6] Tatsuhisa Suzuki,[2] Mamoru Miyano, and Yoshimasa Hosoya.

[7] Yasuhiro Takemoto was announced as the director of the film,[1] while several staff members who had worked on the television series returned, including head writer Masahiro Yokotani, art director Joji Unogochi, and soundtrack composer Tatsuya Kato, among others.

[2] In September 2015, the film's official website had announced new additions to the cast, including Toshiyuki Toyonaga as Asahi, Kouki Uchiyama as Ikuya, Kenji Nojima as Natsuya, and Satoshi Hino as Nao.

[8] Nagisa Hazuki and Rei Ryugazaki, two characters from the main cast of the original Free!

[20] The original soundtrack was produced by Tatsuya Kato, and it was released on December 16, 2015, under the name High Speed!

[22] All tracks are written by Tatsuya KatoTo promote the film, a manga adaptation of High Speed!

Starting Days: Drama CD: Iwatobi Middle School Swim Team Activities Diary (『映画 ハイ☆スピード!-Free!

Starting Days: Dorama CD Iwatobi Chūgaku Suiei-bu Katsudō Nisshi) was released on February 17, 2016, with cast members reprising their roles.